text: /*
   * libjingle
   * Copyright 2004--2011, Google Inc.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   *  1. Redistributions of source code must retain the above copyright notice,
   *     this list of conditions and the following disclaimer.
   *  2. Redistributions in binary form must reproduce the above copyright notice,
   *     this list of conditions and the following disclaimer in the documentation
   *     and/or other materials provided with the distribution.
   *  3. The name of the author may not be used to endorse or promote products
   *     derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
   * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
   * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
   * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
   * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "bruno/stringencode.h"
  
  #include <cstdio>
  #include <cstdlib>
  
  #include "bruno/basictypes.h"
  #include "bruno/common.h"
  #include "bruno/stringutils.h"
  
  namespace bruno_base {
  
  /////////////////////////////////////////////////////////////////////////////
  // String Encoding Utilities
  /////////////////////////////////////////////////////////////////////////////
  
  static const char HEX[] = "0123456789abcdef";
  
  char hex_encode(unsigned char val) {
    ASSERT(val < 16);
    return (val < 16) ? HEX[val] : '!';
  }
  
  bool hex_decode(char ch, unsigned char* val) {
    if ((ch >= '0') && (ch <= '9')) {
      *val = ch - '0';
    } else if ((ch >= 'A') && (ch <= 'Z')) {
      *val = (ch - 'A') + 10;
    } else if ((ch >= 'a') && (ch <= 'z')) {
      *val = (ch - 'a') + 10;
    } else {
      return false;
    }
    return true;
  }
  
  size_t escape(char * buffer, size_t buflen,
                const char * source, size_t srclen,
                const char * illegal, char escape) {
    ASSERT(NULL != buffer);  // TODO: estimate output size
    if (buflen <= 0)
      return 0;
  
    size_t srcpos = 0, bufpos = 0;
    while ((srcpos < srclen) && (bufpos + 1 < buflen)) {
      char ch = source[srcpos++];
      if ((ch == escape) || ::strchr(illegal, ch)) {
        if (bufpos + 2 >= buflen)
          break;
        buffer[bufpos++] = escape;
      }
      buffer[bufpos++] = ch;
    }
  
    buffer[bufpos] = '\0';
    return bufpos;
  }
  
  size_t unescape(char * buffer, size_t buflen,
                  const char * source, size_t srclen,
                  char escape) {
    ASSERT(NULL != buffer);  // TODO: estimate output size
    if (buflen <= 0)
      return 0;
  
    size_t srcpos = 0, bufpos = 0;
    while ((srcpos < srclen) && (bufpos + 1 < buflen)) {
      char ch = source[srcpos++];
      if ((ch == escape) && (srcpos < srclen)) {
        ch = source[srcpos++];
      }
      buffer[bufpos++] = ch;
    }
    buffer[bufpos] = '\0';
    return bufpos;
  }
  
  size_t encode(char * buffer, size_t buflen,
                const char * source, size_t srclen,
                const char * illegal, char escape) {
    ASSERT(NULL != buffer);  // TODO: estimate output size
    if (buflen <= 0)
      return 0;
  
    size_t srcpos = 0, bufpos = 0;
    while ((srcpos < srclen) && (bufpos + 1 < buflen)) {
      char ch = source[srcpos++];
      if ((ch != escape) && !::strchr(illegal, ch)) {
        buffer[bufpos++] = ch;
      } else if (bufpos + 3 >= buflen) {
        break;
      } else {
        buffer[bufpos+0] = escape;
        buffer[bufpos+1] = hex_encode((static_cast<unsigned char>(ch) >> 4) & 0xF);
        buffer[bufpos+2] = hex_encode((static_cast<unsigned char>(ch)     ) & 0xF);
        bufpos += 3;
      }
    }
    buffer[bufpos] = '\0';
    return bufpos;
  }
  
  size_t decode(char * buffer, size_t buflen,
                const char * source, size_t srclen,
                char escape) {
    if (buflen <= 0)
      return 0;
  
    unsigned char h1, h2;
    size_t srcpos = 0, bufpos = 0;
    while ((srcpos < srclen) && (bufpos + 1 < buflen)) {
      char ch = source[srcpos++];
      if ((ch == escape)
          && (srcpos + 1 < srclen)
          && hex_decode(source[srcpos], &h1)
          && hex_decode(source[srcpos+1], &h2)) {
        buffer[bufpos++] = (h1 << 4) | h2;
        srcpos += 2;
      } else {
        buffer[bufpos++] = ch;
      }
    }
    buffer[bufpos] = '\0';
    return bufpos;
  }
  
  const char* unsafe_filename_characters() {
    // It might be better to have a single specification which is the union of
    // all operating systems, unless one system is overly restrictive.
  #ifdef WIN32
    return "\\/:*?\"<>|";
  #else  // !WIN32
    // TODO
    ASSERT(false);
    return "";
  #endif  // !WIN23
  }
  
  const unsigned char URL_UNSAFE  = 0x1; // 0-33 "#$%&+,/:;<=>?@[\]^`{|} 127
  const unsigned char XML_UNSAFE  = 0x2; // "&'<>
  const unsigned char HTML_UNSAFE = 0x2; // "&'<>
  
  //  ! " # $ % & ' ( ) * + , - . / 0 1 2 3 4 6 5 7 8 9 : ; < = > ?
  //@ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z [ \ ] ^ _
  //` a b c d e f g h i j k l m n o p q r s t u v w x y z { | } ~
  
  const unsigned char ASCII_CLASS[128] = {
    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
    1,0,3,1,1,1,3,2,0,0,0,1,1,0,0,1,0,0,0,0,0,0,0,0,0,0,1,1,3,1,3,1,
    1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,0,
    1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,0,1,
  };
  
  size_t url_encode(char * buffer, size_t buflen,
                    const char * source, size_t srclen) {
    if (NULL == buffer)
      return srclen * 3 + 1;
    if (buflen <= 0)
      return 0;
  
    size_t srcpos = 0, bufpos = 0;
    while ((srcpos < srclen) && (bufpos + 1 < buflen)) {
      unsigned char ch = source[srcpos++];
      if ((ch < 128) && (ASCII_CLASS[ch] & URL_UNSAFE)) {
        if (bufpos + 3 >= buflen) {
          break;
        }
        buffer[bufpos+0] = '%';
        buffer[bufpos+1] = hex_encode((ch >> 4) & 0xF);
        buffer[bufpos+2] = hex_encode((ch     ) & 0xF);
        bufpos += 3;
      } else {
        buffer[bufpos++] = ch;
      }
    }
    buffer[bufpos] = '\0';
    return bufpos;
  }
  
  size_t url_decode(char * buffer, size_t buflen,
                    const char * source, size_t srclen) {
    if (NULL == buffer)
      return srclen + 1;
    if (buflen <= 0)
      return 0;
  
    unsigned char h1, h2;
    size_t srcpos = 0, bufpos = 0;
    while ((srcpos < srclen) && (bufpos + 1 < buflen)) {
      unsigned char ch = source[srcpos++];
      if (ch == '+') {
        buffer[bufpos++] = ' ';
      } else if ((ch == '%')
                 && (srcpos + 1 < srclen)
                 && hex_decode(source[srcpos], &h1)
                 && hex_decode(source[srcpos+1], &h2))
      {
        buffer[bufpos++] = (h1 << 4) | h2;
        srcpos += 2;
      } else {
        buffer[bufpos++] = ch;
      }
    }
    buffer[bufpos] = '\0';
    return bufpos;
  }
  
  size_t utf8_decode(const char* source, size_t srclen, unsigned long* value) {
    const unsigned char* s = reinterpret_cast<const unsigned char*>(source);
    if ((s[0] & 0x80) == 0x00) {                    // Check s[0] == 0xxxxxxx
      *value = s[0];
      return 1;
    }
    if ((srclen < 2) || ((s[1] & 0xC0) != 0x80)) {  // Check s[1] != 10xxxxxx
      return 0;
    }
    // Accumulate the trailer byte values in value16, and combine it with the
    // relevant bits from s[0], once we've determined the sequence length.
    unsigned long value16 = (s[1] & 0x3F);
    if ((s[0] & 0xE0) == 0xC0) {                    // Check s[0] == 110xxxxx
      *value = ((s[0] & 0x1F) << 6) | value16;
      return 2;
    }
    if ((srclen < 3) || ((s[2] & 0xC0) != 0x80)) {  // Check s[2] != 10xxxxxx
      return 0;
    }
    value16 = (value16 << 6) | (s[2] & 0x3F);
    if ((s[0] & 0xF0) == 0xE0) {                    // Check s[0] == 1110xxxx
      *value = ((s[0] & 0x0F) << 12) | value16;
      return 3;
    }
    if ((srclen < 4) || ((s[3] & 0xC0) != 0x80)) {  // Check s[3] != 10xxxxxx
      return 0;
    }
    value16 = (value16 << 6) | (s[3] & 0x3F);
    if ((s[0] & 0xF8) == 0xF0) {                    // Check s[0] == 11110xxx
      *value = ((s[0] & 0x07) << 18) | value16;
      return 4;
    }
    return 0;
  }
  
  size_t utf8_encode(char* buffer, size_t buflen, unsigned long value) {
    if ((value <= 0x7F) && (buflen >= 1)) {
      buffer[0] = static_cast<unsigned char>(value);
      return 1;
    }
    if ((value <= 0x7FF) && (buflen >= 2)) {
      buffer[0] = 0xC0 | static_cast<unsigned char>(value >> 6);
      buffer[1] = 0x80 | static_cast<unsigned char>(value & 0x3F);
      return 2;
    }
    if ((value <= 0xFFFF) && (buflen >= 3)) {
      buffer[0] = 0xE0 | static_cast<unsigned char>(value >> 12);
      buffer[1] = 0x80 | static_cast<unsigned char>((value >> 6) & 0x3F);
      buffer[2] = 0x80 | static_cast<unsigned char>(value & 0x3F);
      return 3;
    }
    if ((value <= 0x1FFFFF) && (buflen >= 4)) {
      buffer[0] = 0xF0 | static_cast<unsigned char>(value >> 18);
      buffer[1] = 0x80 | static_cast<unsigned char>((value >> 12) & 0x3F);
      buffer[2] = 0x80 | static_cast<unsigned char>((value >> 6) & 0x3F);
      buffer[3] = 0x80 | static_cast<unsigned char>(value & 0x3F);
      return 4;
    }
    return 0;
  }
  
  size_t html_encode(char * buffer, size_t buflen,
                     const char * source, size_t srclen) {
    ASSERT(NULL != buffer);  // TODO: estimate output size
    if (buflen <= 0)
      return 0;
  
    size_t srcpos = 0, bufpos = 0;
    while ((srcpos < srclen) && (bufpos + 1 < buflen)) {
      unsigned char ch = source[srcpos];
      if (ch < 128) {
        srcpos += 1;
        if (ASCII_CLASS[ch] & HTML_UNSAFE) {
          const char * escseq = 0;
          size_t esclen = 0;
          switch (ch) {
            case '<':  escseq = "&lt;";   esclen = 4; break;
            case '>':  escseq = "&gt;";   esclen = 4; break;
            case '\'': escseq = "&#39;";  esclen = 5; break;
            case '\"': escseq = "&quot;"; esclen = 6; break;
            case '&':  escseq = "&amp;";  esclen = 5; break;
            default: ASSERT(false);
          }
          if (bufpos + esclen >= buflen) {
            break;
          }
          memcpy(buffer + bufpos, escseq, esclen);
          bufpos += esclen;
        } else {
          buffer[bufpos++] = ch;
        }
      } else {
        // Largest value is 0x1FFFFF => &#2097151;  (10 characters)
        char escseq[11];
        unsigned long val;
        if (size_t vallen = utf8_decode(&source[srcpos], srclen - srcpos, &val)) {
          srcpos += vallen;
        } else {
          // Not a valid utf8 sequence, just use the raw character.
          val = static_cast<unsigned char>(source[srcpos++]);
        }
        size_t esclen = sprintfn(escseq, ARRAY_SIZE(escseq), "&#%lu;", val);
        if (bufpos + esclen >= buflen) {
          break;
        }
        memcpy(buffer + bufpos, escseq, esclen);
        bufpos += esclen;
      }
    }
    buffer[bufpos] = '\0';
    return bufpos;
  }
  
  size_t html_decode(char * buffer, size_t buflen,
                     const char * source, size_t srclen) {
    ASSERT(NULL != buffer);  // TODO: estimate output size
    return xml_decode(buffer, buflen, source, srclen);
  }
  
  size_t xml_encode(char * buffer, size_t buflen,
                    const char * source, size_t srclen) {
    ASSERT(NULL != buffer);  // TODO: estimate output size
    if (buflen <= 0)
      return 0;
  
    size_t srcpos = 0, bufpos = 0;
    while ((srcpos < srclen) && (bufpos + 1 < buflen)) {
      unsigned char ch = source[srcpos++];
      if ((ch < 128) && (ASCII_CLASS[ch] & XML_UNSAFE)) {
        const char * escseq = 0;
        size_t esclen = 0;
        switch (ch) {
          case '<':  escseq = "&lt;";   esclen = 4; break;
          case '>':  escseq = "&gt;";   esclen = 4; break;
          case '\'': escseq = "&apos;"; esclen = 6; break;
          case '\"': escseq = "&quot;"; esclen = 6; break;
          case '&':  escseq = "&amp;";  esclen = 5; break;
          default: ASSERT(false);
        }
        if (bufpos + esclen >= buflen) {
          break;
        }
        memcpy(buffer + bufpos, escseq, esclen);
        bufpos += esclen;
      } else {
        buffer[bufpos++] = ch;
      }
    }
    buffer[bufpos] = '\0';
    return bufpos;
  }
  
  size_t xml_decode(char * buffer, size_t buflen,
                    const char * source, size_t srclen) {
    ASSERT(NULL != buffer);  // TODO: estimate output size
    if (buflen <= 0)
      return 0;
  
    size_t srcpos = 0, bufpos = 0;
    while ((srcpos < srclen) && (bufpos + 1 < buflen)) {
      unsigned char ch = source[srcpos++];
      if (ch != '&') {
        buffer[bufpos++] = ch;
      } else if ((srcpos + 2 < srclen)
                 && (memcmp(source + srcpos, "lt;", 3) == 0)) {
        buffer[bufpos++] = '<';
        srcpos += 3;
      } else if ((srcpos + 2 < srclen)
                 && (memcmp(source + srcpos, "gt;", 3) == 0)) {
        buffer[bufpos++] = '>';
        srcpos += 3;
      } else if ((srcpos + 4 < srclen)
                 && (memcmp(source + srcpos, "apos;", 5) == 0)) {
        buffer[bufpos++] = '\'';
        srcpos += 5;
      } else if ((srcpos + 4 < srclen)
                 && (memcmp(source + srcpos, "quot;", 5) == 0)) {
        buffer[bufpos++] = '\"';
        srcpos += 5;
      } else if ((srcpos + 3 < srclen)
                 && (memcmp(source + srcpos, "amp;", 4) == 0)) {
        buffer[bufpos++] = '&';
        srcpos += 4;
      } else if ((srcpos < srclen) && (source[srcpos] == '#')) {
        int int_base = 10;
        if ((srcpos + 1 < srclen) && (source[srcpos+1] == 'x')) {
          int_base = 16;
          srcpos += 1;
        }
        char * ptr;
        // TODO: Fix hack (ptr may go past end of data)
        unsigned long val = strtoul(source + srcpos + 1, &ptr, int_base);
        if ((static_cast<size_t>(ptr - source) < srclen) && (*ptr == ';')) {
          srcpos = ptr - source + 1;
        } else {
          // Not a valid escape sequence.
          break;
        }
        if (size_t esclen = utf8_encode(buffer + bufpos, buflen - bufpos, val)) {
          bufpos += esclen;
        } else {
          // Not enough room to encode the character, or illegal character
          break;
        }
      } else {
        // Unrecognized escape sequence.
        break;
      }
    }
    buffer[bufpos] = '\0';
    return bufpos;
  }
  
  std::string hex_encode(const char * source, size_t srclen) {
    const size_t kBufferSize = srclen * 2 + 1;
    char* buffer = STACK_ARRAY(char, kBufferSize);
    size_t length = hex_encode(buffer, kBufferSize, source, srclen);
    return std::string(buffer, length);
  }
  
  size_t hex_encode(char * buffer, size_t buflen,
                    const char * csource, size_t srclen) {
    ASSERT(NULL != buffer);  // TODO: estimate output size
    if (buflen <= 0)
      return 0;
  
    const unsigned char * bsource =
      reinterpret_cast<const unsigned char *>(csource);
  
    size_t srcpos = 0, bufpos = 0;
    srclen = _min(srclen, (buflen - 1) / 2);
    while (srcpos < srclen) {
      unsigned char ch = bsource[srcpos++];
      buffer[bufpos  ] = hex_encode((ch >> 4) & 0xF);
      buffer[bufpos+1] = hex_encode((ch     ) & 0xF);
      bufpos += 2;
    }
    buffer[bufpos] = '\0';
    return bufpos;
  }
  
  size_t hex_decode(char * cbuffer, size_t buflen,
                    const char * source, size_t srclen) {
    ASSERT(NULL != cbuffer);  // TODO: estimate output size
    if (buflen <= 0)
      return 0;
  
    unsigned char * bbuffer = reinterpret_cast<unsigned char *>(cbuffer);
  
    unsigned char h1, h2;
    size_t srcpos = 0, bufpos = 0;
    while ((srcpos + 1 < srclen)
           && (bufpos + 1 < buflen)
           && hex_decode(source[srcpos], &h1)
           && hex_decode(source[srcpos+1], &h2))
    {
      bbuffer[bufpos++] = (h1 << 4) | h2;
      srcpos += 2;
    }
    bbuffer[bufpos] = '\0';
    return bufpos;
  }
  
  size_t transform(std::string& value, size_t maxlen, const std::string& source,
                   Transform t) {
    char* buffer = STACK_ARRAY(char, maxlen + 1);
    size_t length = t(buffer, maxlen + 1, source.data(), source.length());
    value.assign(buffer, length);
    return length;
  }
  
  std::string s_transform(const std::string& source, Transform t) {
    // Ask transformation function to approximate the destination size (returns upper bound)
    size_t maxlen = t(NULL, 0, source.data(), source.length());
    char * buffer = STACK_ARRAY(char, maxlen);
    size_t len = t(buffer, maxlen, source.data(), source.length());
    std::string result(buffer, len);
    return result;
  }
  
  size_t tokenize(const std::string& source, char delimiter,
                  std::vector<std::string>* fields) {
    ASSERT(NULL != fields);
    fields->clear();
    size_t last = 0;
    for (size_t i = 0; i < source.length(); ++i) {
      if (source[i] == delimiter) {
        if (i != last) {
          fields->push_back(source.substr(last, i - last));
        }
        last = i + 1;
      }
    }
    if (last != source.length()) {
      fields->push_back(source.substr(last, source.length() - last));
    }
    return fields->size();
  }
  
  size_t tokenize_append(const std::string& source, char delimiter,
                         std::vector<std::string>* fields) {
    if (!fields) return 0;
  
    std::vector<std::string> new_fields;
    tokenize(source, delimiter, &new_fields);
    fields->insert(fields->end(), new_fields.begin(), new_fields.end());
    return fields->size();
  }
  
  size_t tokenize(const std::string& source, char delimiter, char start_mark,
                  char end_mark, std::vector<std::string>* fields) {
    if (!fields) return 0;
    fields->clear();
  
    std::string remain_source = source;
    while (!remain_source.empty()) {
      size_t start_pos = remain_source.find(start_mark);
      if (std::string::npos == start_pos) break;
      std::string pre_mark;
      if (start_pos > 0) {
        pre_mark = remain_source.substr(0, start_pos - 1);
      }
  
      ++start_pos;
      size_t end_pos = remain_source.find(end_mark, start_pos);
      if (std::string::npos == end_pos) break;
  
      // We have found the matching marks. First tokenize the pre-mask. Then add
      // the marked part as a single field. Finally, loop back for the post-mark.
      tokenize_append(pre_mark, delimiter, fields);
      fields->push_back(remain_source.substr(start_pos, end_pos - start_pos));
      remain_source = remain_source.substr(end_pos + 1);
    }
  
    return tokenize_append(remain_source, delimiter, fields);
  }
  
  size_t split(const std::string& source, char delimiter,
               std::vector<std::string>* fields) {
    ASSERT(NULL != fields);
    fields->clear();
    size_t last = 0;
    for (size_t i = 0; i < source.length(); ++i) {
      if (source[i] == delimiter) {
        fields->push_back(source.substr(last, i - last));
        last = i + 1;
      }
    }
    fields->push_back(source.substr(last, source.length() - last));
    return fields->size();
  }
  
  char make_char_safe_for_filename(char c) {
    if (c < 32)
      return '_';
  
    switch (c) {
      case '<':
      case '>':
      case ':':
      case '"':
      case '/':
      case '\\':
      case '|':
      case '*':
      case '?':
        return '_';
  
      default:
        return c;
    }
  }
  
  /*
  void sprintf(std::string& value, size_t maxlen, const char * format, ...) {
    char * buffer = STACK_ARRAY(char, maxlen + 1);
    va_list args;
    va_start(args, format);
    value.assign(buffer, vsprintfn(buffer, maxlen + 1, format, args));
    va_end(args);
  }
  */
  
  /////////////////////////////////////////////////////////////////////////////
  
  }  // namespace bruno_base
  